Method Subjects Three water-deprived male- Wistar rats. Apparatus

1. Low-cost USB interface with Arduino and Visual Basic for experimental controlRogelio Escobar and Carlos Alexis Pérez-HerreraNational Autonomus University of Mexico . Because of the increasing popularity of microcontroller boards, interfaces for controlling operant conditioning chambers can be built at low cost with barely any knowledge of electronics. The arduino board meets the requirements of accuracy and long term performance in operant conditioning experiments and is available worldwide. Additionally, a collection of open source code that can be used in a variety of applications is available. This board in combination with an accessible programing language and a low-cost experimental chamber could help establishing new operant conditioning laboratories around the world. This poster describes the implementation and testing of a low cost interface using the Arduino board in combination with Visual Basic 2010 Express Edition (VBEE). Introduction Experiment In To determine the stability and accuracy of the interface, tests were conducted using FI schedules of reinforcement. The arduino board was connected to a cumulative recorder to compare the obtained patterns of responding to those reported previously. • Method • Subjects • Three water-deprived male-Wistar rats. • Apparatus • An operant chamber containing a lever, a 24 v water valve (Skinner, V5J71710) and a houselight, was connected to a laptop computer using the Arduino-VBEE interface. • Procedure • 30 sessions FI 30 s • 40 sessions FI 60 s The microcontroller within the Arduino is programmed to activate the devices when data is received from VBEE, and to read continuously the value of the digital input. Interface In The Arduino is an open-source prototyping input-output board that can serve to establish communication with a PC trough the USB port. This port is used to upload programs to the microcontroller and to send and receive real-time data. The board is equipped with 14 digital and 6 analog input/output pins that can be used to control and record the events in an operant conditioning chamber. Results RC1 RC2 RC3 To communicate with VBEE, the Arduino is declared as a serial port within a module. In the example ComPort = COM4, as specified in the Device Manager. RC1 Digital switches like levers, can be connected to a digital input. The common pin of a lever was connected to digital input 8 using a 10 KΩ resistor, and the normally open pin was connected to ground. A 28 v power supply was added to power a bulb that served as houselight, and a solenoid valve that delivered 0.1 ml of water. The Arduino was connected to an array of 5 V relays with the integrated circuit ULN2803. This arrangement eliminates the use of protective diodes and transistors for each relay. Therefore, setting pins 11 and 12 to high turned on the 28 v devices in the chamber by changing the state of the relays. RC2 A fixed-interval (FI) schedule can be programmed with few lines of code in VBEE. RC3 This screen was designed to show the relevant data during the experiment. Conclusions In • The Arduino board in combination with VBEE is a reliable and accurate low-cost alternative to commercial equipment for conducting operant conditioning experiments. An important advantage over other interfaces is that it can be implemented with any computer with an available USB port and running VBEE . The Arduino connected to the array of relays The solenoid valve and the front panel • This project was developed under the 2012 SABA International Development Grantand PAPIIT project TA300213-2, DGAPA UNAM,awarded to the first author.